package com.itext5.xfdfReader;

/*
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2016 iText Group NV
* Authors: Kevin Day, Bruno Lowagie, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
* ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
* OF THIRD PARTY RIGHTS.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Affero General License for more
* details. You should have received a copy of the GNU Affero General License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General License.
*
* In accordance with Section 7(b) of the GNU Affero General License, a covered
* work must retain the producer line in every PDF that is created or
* manipulated using iText.
*
* You can be released from the requirements of the license by purchasing a
* commercial license. Buying such a license is mandatory as soon as you develop
* commercial activities involving the iText software without disclosing the
* source code of your own applications. These activities include: offering paid
* services to customers as an ASP, serving PDFs on the fly in a web
* application, shipping iText with a closed source product.
*
* For more information, please contact iText Software Corp. at this address:
* sales@itextpdf.com
*/
import java.io.ByteArrayOutputStream;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
* Utility class with commonly used stream operations
* @since 5.3.5
*
*/
public final class StreamUtil {

   private StreamUtil() {
   }

   /**
    * Reads the full content of a stream and returns them in a byte array
    * @param is the stream to read
    * @return a byte array containing all of the bytes from the stream
    * @throws IOException if there is a problem reading from the input stream
    */
   public static byte[] inputStreamToArray(InputStream is) throws IOException {
       byte b[] = new byte[8192];
       ByteArrayOutputStream out = new ByteArrayOutputStream();
       while (true) {
           int read = is.read(b);
           if (read < 1)
               break;
           out.write(b, 0, read);
       }
       out.close();
       return out.toByteArray();
   }

   public static void CopyBytes(RandomAccessSource source, long start, long length, OutputStream outs) throws IOException {
       if (length <= 0)
           return;
       long idx = start;
       byte[] buf = new byte[8192];
       while (length > 0) {
           long n = source.get(idx, buf,0, (int)Math.min((long)buf.length, length));
           if (n <= 0)
               throw new EOFException();
           outs.write(buf, 0, (int)n);
           idx += n;
           length -= n;
       }
   }

   /**
    * Gets the resource's inputstream.
    * @param key the full name of the resource
    * @return the <CODE>InputStream</CODE> to get the resource or
    * <CODE>null</CODE> if not found
    */
   public static InputStream getResourceStream(String key) {
       return getResourceStream(key, null);
   }

   /**
    * Gets the resource's inputstream
    * .
    * @param key the full name of the resource
    * @param loader the ClassLoader to load the resource or null to try the ones available
    * @return the <CODE>InputStream</CODE> to get the resource or
    * <CODE>null</CODE> if not found
    */
   public static InputStream getResourceStream(String key, ClassLoader loader) {
       if (key.startsWith("/"))
           key = key.substring(1);
       InputStream is = null;
       if (loader != null) {
           is = loader.getResourceAsStream(key);
           if (is != null)
               return is;
       }
       // Try to use Context Class Loader to load the properties file.
       try {
           ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
           if (contextClassLoader != null) {
               is = contextClassLoader.getResourceAsStream(key);
           }
       } catch (Throwable e) {
           // empty body
       }

       if (is == null) {
           is = StreamUtil.class.getResourceAsStream("/" + key);
       }
       if (is == null) {
           is = ClassLoader.getSystemResourceAsStream(key);
       }
       return is;
   }
}

